The present invention relates to pattern recognition systems and, more particularly, to pattern recognition systems operating on a real-time basis.
Pattern recognition systems have gained rapid acceptance and have been utilized in numerous applications since the advent of contemporary computer technology. Supermarket check-out lines include devices to scan the pre-marked products, virtually eliminating the old cash register button entry system. Word processing systems scan previously typewritten pages and digitize the data thus eleminating time consuming keyboard entry of text into the computer.
Most such systems, however, are limited to recognizing simple patterns such as single letters and product bar codes. Alignment and position within the scanned field can be a critical factor. Typically, the scanned character is digitized and the digital value scanned against a previously stored table of digital values for a match. In the absence of a match, the symbol goes unrecognized. A lack of proper character orientation at the time of scanning and digitization can result in a mis-digitization such that no recognition or a mis-recognition occurs.
Spatial filtering can be employed in character recognition with the advantage of positioning no longer being a factor. That is, a character or symbol at any position within the optic field will create a unique spatial filter pattern at the Fourier plane.
Wherefore, it is the object of the present invention to provide a character recognition system employing dynamically changeable spatial filtering techniques.